Our goals in Phases I and II have been completed and showed the feasibility of our approach for assessing brain vascular autoregulatory responses to hypoxic stimuli. Frequency Domain Near-Infrared Spectroscopy offers the advantage of performing safe, non-invasive, transcranial, quantitative, real time measurements of cerebral hemodynamics and oxygenation. Our main objective was the launch of this technique in Sleep Medicine Research. The standard diagnostic instrumentation (polysomnography) used in Sleep Medicine gives important information on the functionality of different systems. However, it does not provide the clinician with information on cerebral oxygenation and hemodynamics during sleep, that are important factors to determine. The assessment of these parameters, via near infrared spectroscopy, in Obstructive Sleep Apnea sufferers is crucial because of the high prevalence of this affliction and of the significant cardio/cerebrovascular health risk it represents. Although this has been a technical research proposal, we have been excited with the enormous potential of the scientific information we obtained during the few preclinical trials of Phase II of this application. We developed the first commercially available Absolute Near-Infrared Oximeter (OxiplexTS). This is a portable device that may be applied in conjunction with other devices such as the standard polysomnography equipment to monitor the severity of the apneic insult on the brain during overnight testing. This instrumentation may be also applied as a stand alone tool to facilitate cost-effective early detection and screening of morbid cardio/cerebrovascular effects of medical conditions such as Obstructive Sleep Apnea Syndrome. In this Phase III clinical trial we propose to perform the necessary number of clinical studies required by the Food and Drug Administration (FDA) for Investigational New Devices and assess performance standards of OxiplexTS related to the FDA approval process. The overall goal of ISS, Inc. is the commercialization of an FDA approved instrument for applications in Sleep Medicine as well as in the broader field of clinical cardiovascular/cerebrovascular diagnostics. The socioeconomic benefit lies in identifying patients at cardiovascular risk. Subsequent timely treatment minimizes costly therapy of the cardiovascular and cerebrovascular sequelae of disorders such as sleep apnea as well as reduces mortality. Our ultimate goal is the FDA approval and the introduction of the Frequency Domain Near-infrared Brain Oximeter (OxiplexTS) in clinical diagnostics for the investigation of brain oxygenation and hemodynamics. The evaluation of brain vascular autoregulatory responses to hypoxia and hypercapnia enable the assessment of the brain vascular health. The socioeconomic benefit lies in identifying patients at cerebrovascular risk. Subsequent timely treatment minimizes costly therapy of the cardiovascular and cerebrovascular sequelae of disorders such as Obstructive Sleep Apnea as well as reduces mortality.